' % \
(self.get_id() + value , self.__class__.__name__, field_name, checked_html,
self.get_id() + value, choice))
It generates a list that overlaps the checkbox labels with the next checkbox, in order to generate a list that has its elements one under the other that line should render a class=""vCheckboxLabel"" for the label like this:
(Line 586 of formfields.py in django/core/):
output.append('